Nationwide, homeless populations are at risk for HIV infection due to disproportionate use of injection drug use, unprotected sexual activity, prostitution and victimization. There is increasing suspicion that infection with the Hepatitis B Virus (HBV) and the Hepatitis C Virus (HCV) are silently escalating among homeless adults as they share risk factors with HIV. Thus, education and screening programs for HBV, HCV and HIV, combined with vaccination programs for HBV, can significantly decrease morbidity and mortality. However, HBV vaccination programs among homeless persons, many of whom may be contending with drug and alcohol abuse, unemployment, language barriers and live in a disorganized world with little access to health and social services, have not been systematically tested. In this prospective four group quasi-experimental design, we will evaluate with approximately 1254 sheltered men and women in the Skid Row area of Los Angeles, the effectiveness of a theoretically-based HBV vaccination intervention focused primarily on completion of the HBV vaccination series and secondarily on HBV/HCV/HIV risk reduction. We will also evaluate the relative cost of each of these programs in terms of completion of HBV vaccination, the cost effectiveness of improving vaccination completion, the cost per seroprotected case, and the cost per infection prevented. Once determined eligible, participants will be randomized by shelter into one of four programs: a Nurse Case Managed Plus Incentive (NCMI) program, a Nurse Case Managed without Incentive (NCM) program (both of which provide tracking), an Incentive with tracking (IT), and an Incentive-Only (I-O) program without tracking. The proposed study is innovative in that the inclusion of an NCMI program, an NCM program, an IT program, and an I-O program will allow us to look at individual effects of nurse case management and incentives separately, the joint effect of both together, and the impact of tracking in terms of completing the HBV vaccination series. Participants in all four programs will receive the 3-series vaccination by trained research nurses at the study clinic over six months, along with either an enhanced HBV/HCV/HIV education program (NCMI and NCM), or a brief HBV/HCV/HIV (IT and I-O) education program. All participants will be assessed at baseline and six- and twelve-month follow-up using a battery of psychosocial, behavioral, health and physical status, as well as HBV, HCV and HIV serostatus measurements. This proposed study supports the National Drug Abuse Research Initiative as it is focused on assessing the effectiveness of intervention programs promoting the prevention of medical consequences of HBV/HCV/HIV in homeless and drug-abusing populations. [unreadable] [unreadable]